My LCD computer monitor has been playing up. When you turn the brightness down it comes up with dark horizontal lines going down the screen about 1" long. Any ideas how this could be fixed thanks. Jeremy

Have you tried another monitor to make sure it is the monitor and not something else? You may have to replace the monitor anyway

the computer works fine, i know its the monitor. the monitor has been repaired under warranty before, but it's no longer covered under warranty.

It can't
Here's your options:

1. Leave the brightness up, and try adjust your Windows display settings as best as possible
2. Buy a new LCD